sister

(noun) a female person who has the same parents as another person. Synonyms: sis. Example: "My sister married a musician."

(noun) (Roman Catholic Church) a title given to a nun (and used as a form of address). Synonyms: Sister. Example: "The sisters taught her to love god."

(noun) a female person who is a fellow member of a sorority or labor union or other group. Example: "None of her sisters would betray her."

(noun) (slang) sometimes used as a term of address for attractive young women. Synonyms: baby, babe.